(I'm making this post mostly so I don't have to keep arguing these points and can just send this link instead)
I believe in free will. I believe people have free will, and I believe a roomba has free will.
What I mean by free will is this: the decision that an agent makes is the result of that agent's thinking process.
It does not matter that that thinking process happens to run on a computer (brain for the person, chip for the roomba) which is based on deterministic (or quantum-random) physics; the output of that decision is the result of deterministic (or quantum-random) phenomena, this is true, but also the result of that thinking process. Both are true, they merely are facts about different layers of reality.
Here's evidence that the decision the human/roomba makes is actually the result of their thinking process: if an outside party interfered with the thinking process, then the resulting decision could be different.
edit: i've been informed this position might be called compatibilism.